Varying the voltage of a carrier or a direct current in order to transmit analog or digital data. Amplitude modulation (AM) is the oldest method of transmitting human voice electronically. In an ...

AM, or amplitude modulation, was the earliest way of sending voice over radio waves. That makes sense because it is easy to modulate a signal and easy to demodulate it, as well. A carbon microphone is ...

Last month we looked at contributions to the art made by amateur operators, in particular advancements in Amplitude Modulation, or AM, and how it came to give radio its voice. This month, we will look ...

Electrified telegraphy was the first practical use of electricity for long-distance communication. This was a tremendous improvement over flashing lights and waving signal flags. The well-known Morse ...

A 10-MHz sinusoidal carrier wave of amplitude 10 mV is modulated by a 5-kHz sinusoidal audio signal wave of amplitude 6 mV. Find (a) the frequency components of the resultant modulated wave and (b) ...

Modulation is the process of varying a higher frequency carrier wave to transmit information. Though it is theoretically possible to transmit baseband signals (or information) without modulating it, ...

Changing the amplitude of a radio wave. A higher wave is interpreted as a 1 and a normal wave is interpreted as a zero. By changing the wave, the RFID tag can communicate a string of binary digits to ...